1990年5～6月江苏省南通市城区发生了急性病毒性肝炎(急肝)的暴发,在疫情上升的初期,我们组织有关人员对这次暴发进行了流行病学调查。城区卫生防疫站逐日搜集各医院急肝报告卡;分别调查4月份各种可疑食物史、肝炎接触史等17个因素;8月份在典型地区了解人群食用泥螺等可疑食品与发病的关系;同时对产地泥螺进行甲肝病毒核酸斑点杂交试验(由中国预防医学院病毒所与江苏省卫生防疫站共同完成)。流行特征1990年5月1日出现首例急肝患者,后发病数逐步上升,中旬达高峰,6月 From May to June 1990, an outbreak of acute viral hepatitis (acute liver) occurred in Nantong City, Jiangsu Province. During the initial period of the epidemic rising, we organized relevant personnel to conduct an epidemiological investigation on this outbreak. Urban health and epidemic prevention stations daily collection of the hospital acute liver report card; were investigated in April various suspicious food history, history of hepatitis exposure 17 factors; in August in a typical area to understand the crowd eating mud snail and other suspicious foods and the incidence; Hepatitis C virus spot blot hybridization test was conducted on the local snails (jointly completed by the Chinese Academy of Preventive Medicine and Jiangsu Provincial Health and Epidemic Prevention Station). Epidemic characteristics May 1, 1990 the first case of acute liver disease, the number of cases after the gradual rise in mid-peak, in June